Drill.



A. BLAUVELT.

DRILL.

APPLICATION FILED FEB.19, |912.

11119D1611 loma. 31,1916.

2 SHEETS-SHEET I.

L ,A111 d 1 i 5. 7

A. BLAUVELT.

` DRILL.

APPLICATION FILED FEB. 19.4912.

j. Patented oet. 31, 19116.

2 SHEETS-SHEET 2.

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ALBERT BLAUVELT, OF CHICAGO, XLLINOS.

DRILL.

Specnc-etters atent. Patente-)dl (het. 3.1L., 19h45.,

Application filed February 19, 1912. Serial No. 678,540.

T all 'whom t` may concern.'

lie it known that l, ALBERT BLAUVELT, a

citizen of the lUnited States, residing at Chicago, county of Cook, and State of lllinois, have invented certain new and useful lmprovements in Drills, of which the following is a specification. i

My invention relates particularly to drills for operating upon metals and other very resistant material. llt is well known that in drills ordinarily employed for this purpose the resistance to penetration is largely at the chisel point or center of the drill. 'll his resistance is not very great in drills of small caliber, but as the diameter of the drill is increased it becomes proportionallv greater because of tlie wider chisel point essential to web strength oflarge drills. So great does this objection become 1n the larger sized drills, that it is a common practice in many classes of work to first drill a small hole by a rapid running small drill and subsequently enlarge the hole by following it with a drill of the diameter required, notwithstanding th-e fact that this operation requires a change of drill and a change of speed in the drill operating mechanism.

lt is the purpose of my present invention to obviate the necessity of employing these speed changes and great pressures on drills of large diameter'without encountering the4 inconveniences and delays which result from using first a smallv and then a large drill, as referred to above.

With this object in view, my invention in its broader aspect consists in employing 'a pair of concentric drills, `the 'smaller of which revolves within an` axial bore in the larger drill or router, with means for turn-- ing the smaller tool at a higher rate of rotation than is given to the larger tool.

ln the accompanying drawings l have shown a preferred form or embodiment of my invention, and in the following specifica.

tion l have specifically described the same. lt'is to be understood, however, that the drawing is merely illustrative of a preferred v form or embodiment, and that my invention is not limited thereto, but includes the many equivalent forms which come within the scope of the following claims.

Referring now 1 is a longitudinalsection of the drive end of a drill machine having my improved drill y slot above referred to.

to the drawings, Figure.

attached thereto and shown partly in section and partly in elevation. Fig. 2 is a crosssection of a drill upon the line 2-2 of Fig. 1. Fig. 3 is an elevation of the chuck body of the drill, with certain parts thereof removed to yshow the interior construction. Fig. 4L is an elevation showing the concentric drillslor bits as they are in operation, the material in which a hole is being drilled being shown in section. Fig. 5 is a central longitudinal section of the outer drill or router, the inner drill being shown in elevation. Fig. 6 is a transverse section on the line 6--6 of Fig-5. Fig. 7 is a transverse section on the line 7 7 of Figf -4. Fig. 8 1s a view comprising perspectives of the-upper end of the router and an element of the chuck body with which it engagea Figs. 9 and 10 are .fragmentary views of different applications, the former showing a pilot drill and sweep cutter in elevation, and'Fig. 10 adrill followed by a tap, the latter in lon itudinal section. f

ll/y'f" invention is adapted to be applied to any usual form of drill machine, and in Fig. A

'slot 18 within which is mounted a set of gears numbered 19, 20, and 21, respectively. rFhe bore of the clutch socket 17 is continued axially of the forging until it intersects the At its lower end the clutch socket is exteriorly screw-threaded, as at 23, and longitudinally slit, as at 24, and with the screw thread engages a wingv nut 25 for the purpose of contracting the clutch socket to grip and steady the shank of the bit or drill 26' inserted therein. lt is not, however, 'by this frictional grip that the drill is rotated, but a positive drive is prgvided by a transverse groove 27 in thevnpper end of the router engaging the lugs 28 upon a sleeve 29 fitted within the extension ofthe socket at its upper end. ln

-order to prevent movement of the sleeve 29 with the chuck body with i' tem of gearing with reference to the chuck body, I provide registering transverse bores in the body and sleeve respectively, vinto which are pressed or driven the pins 32,33. The gears 19, 20, and 21, above referred to,are journaled in the upper and lower walls of the transverse chamber by pins 34, 35, 36. The pins 34, 35,

and 36 are pressed fits to be substantially integral with gears 19, 20, and 21.

cavity in the chuck body', and again jour-- naled at its lower end in a bushing 43, which bushing is pressed in the bore of the sleeve 29. i

At its lower end the pin 35 is provided with a head 44 which is provided with an axial slot which receives the flat 54 of the inner drill member or bit 45. It will thus be seen that the inner drill revolves with the pinion and pin 20-35, while the outer drill or router turns with the chuck body l5.

In order to-revolve the pinion 20 at the proper speed, an annular internal gear 46 surrounds the enlargement of the chuck body and engages the idler pinions 19, 21 which project somewhat beyond the periphery of said enlargement. The internal gear is held between the upper and lower meinbers 47, 48' of a casing or shell body, screws 49, 49 extending through flanges on the shell section and the intermediate internal gear for this purpose. In order to prevent the casing and internal gear from rotating reference to which it is free to revolve, being journaled at l22 and 23, the upper portion of the shell has an ear 50 which is perforated to receivea rod 5l clamped or otherwise secured to a stop 52 upon the drive end of the. drill machine. With this construction, it will be apparent that, with the casing held from rotation, the ordinary effect of a planetary 'syswill be had, and the central pinion carrying the inner drill or bit will be rotated at a higher rate of speed than the chuck body carrying the outer drill or router. 1

r.Various forms of drills suitable for use with my improved chuck body are shown in Figs. 4, 5, 6, 7, 9'and 10. In that shown in Figs.l 4 to 7, inclusive, the shank of the bit 53 is cylindrical, but it is provided withy a flat 54 at its upper end for engagement with the recess in the head 44 above referred to, land at lits lower end has the usual standard double twist, as shown. lThis bit is inserted into the axial cavity of the router 26, the

bore of which is of two diameters, the lower .portion 56 thereof snugly fitting the inner drill, and the upper portion 57 slightly enlarged to permit some play. Upon the inner tudinal slot or opening ,62 is formed between' the bottom of the groove and the central bore for the passage of the chips or borings formed by and 7).

As shown more particularly in Figs. 6 and 7 the main drill or router is not truly cylindrical for in addition to the groove which receives the chips there are depressions 63, 63 upon opposite sides of the drill body leaving only the shoulders 64, 64 'and the section 65 Yopposite the groove of the maximum radius of the drill body, and therefore adapted to come into contact'with the wall of the hole being drilled, the relieved portions 63, 63 reducing the friction of the drill with the wall of the cavity. It will of the inner drill (see Figs. 4, 5

course be understood that as usual in drills i of this character the end of the tool is not truly conical but retreats or is relieved from the cuttingedge in the form of a spiral, so

that the` cutting edge alone or the metal region opposite the groove; hence the comparatively broad bearing surface 65 above referred to. By constructing the router with a single cutting edge the extent of chisel edge to be forced into the metal is half that presented by the ordinary form of drill of equal size having two cutting edges, and hence in this respect also the pressure requiredv to hold the drill to its work is reduced. But the pressure required to drive my drill is mainly reduced as compared with the ordinary twist drills in general use by the substantial elimination of the blunt chisel point or edge extending from one groove to the other in such drills. The metal in the'work to be drilled in line with this central edge is not chipped or cut away as is that removed by the cutting edges, but

must be either rubbed away or displaced lat erable size it will be seen that this operation' alone requires great pressure for in order to obtain the requisite web strength the drill must be fairly thick at this point. In my recense drill the corresponding core of metal is removed by the small inner drill or bit and the resistance other than that required by the cutting edges is reduced to what is necessary.

to-force ahead the chisel point or center of the small drill.

In Fig. 9 is disclosed a tool in which the outer member takes the form of a channeling drill comprising a body portion 66 with a shank member 67 and a pair of router-S68, 68, having chisel edges as usual. The central bit 69 in this instance drills a hole for the purpose of centering the main drill, which in operation does not remove the entire body ot' metal within its radiusfbut cuts a channel about a circular disk which is removed as a whole. rllhe outer ends of the drill members may be formed and attached to the chuck body as in the previously described modification.

In Fig. l0 is shown another form of tool which may be used in connection with my chuck. lln this instance the inner member 70 ears at its lower end an enlarged bit 71 whil the outer member 72 is threaded as' at 73 and slightly tapered, the lower entering end being of substantially the diam-eter of the bit 71 which backs up against the lower face of the threaded member. rlhe inner and\outer members are formed at their upper ends as are the members of the Atools previously described and may be engaged by the chuck inthe same manner. lln using this tool the bit 71 drills a hole in the material operated upon and is `followed by the member 72 which forms in edect a tap for threading the opening produced. Obviously the member 72 is not truly circular in cross section but is provided with grooves as is usual in implements of this character which serve the additional function of passages for the chips formed by the bit 71. i

1. lin a device of the class described, a main drilli having a bore, a supplemental drill within the bore, a chuck body for holding and rotating the main drill, and means engaging the supplemental drill and operated by the chuck body for rotating the supplemental drill at a greater speed than the main drill,l l

2. ln a device of the class described, a chuck body having a socket, a main drill, the shank of which is received within said socket for rotation with the chuck body, a supplemental drill co-axial with the main drill, a member rotatable relatively to the chuck body receiving and rotating the supplemental drill and means for transmitting motion from the chuckbody to the Vrotatable member.

3. ln a device of the class described, a main drill, a supplemental drill coaxial therewith, a chuck body by which the mainA drill is held., a coaxial pinion engagingv and 5. ln a device of the class described, a chuck body having a socket for the reception of a router, a head coaxial with the socket and adapted to receive a bit, a pinion rigidly connected to the head to rotate therewith and mounted in the chuck body, and gearing intermediate the chuck body and said pinion for rotating the latter trom the former.

6. lln a device of the class described, n chuck body-having a socket for the rereption of a main drill, a pinion carrying a head for the reception of the shank of a coaxial bit mounted in the chuck body, an internal gear member also mounted upon the chuck body with provision for rotary motion -between said member and body, and gears mounted upon the chuk body intermediate the pinion and said internal gear for transmitting motion from the chuck body to the pinion.

7. ln a device ot the class described, a chuck body having a coaxial socket to receive a tool and a transverse chamber, a pinion mounted in the transverse chamber coaxial with the socket and carrying a head to engage a bit shank, idler gears also mounted in said transverse chamber and engaging said pinion, an internal gear ring surrounding and engaging the gears with provision for rotation between the same and the chuck body whereby motion from the chuck body is transmitted to the pinion.

8. lin a device of the class described, a chuck body having a transverse chamber and a drill socket, a pinion mountedin the transverse chamber in axial alinement with the socket and carrying a head for engaging the shank of a bit,`idler gears also mounted inv said chamber and engaging the pinion, an internal gear ring surrounding and engaging the idler gears, casing members mounted on the chuck body with provision i to the chuck body, gearing between the pinion and the chuck body for driving the former from the latter but at a different speed, a sleeve 29 in the upper end -of the socket and adapted to receive the thrust of the drill, lugs upon the lower end of the sleeve adapted to engage the. end of the drill for rotating the same, and pins 32 for preventing rotation between the chuck body and sleeve.

10. In a device of the class described, a bit member, a router member mounted up'on the same and coaxial therewith having a single cutting edge and a groove for receiving the chips and means for giving independent -rotation to said two members, the Shanks of vgiving independent rotation to the two members.

i ALBERT BLAUVELT.

Witnesses J oHN B. MACAULEYY, ROBERT DOBBERMAN. 

